1. Field of the Invention
The subject invention pertains to portable turntables, in general, and specifically to turntables for use in microwave ovens.
2. The Prior Art
Conventional microwave ovens typically include a high frequency wave generator which sources microwave energy to the interior of a heating cavity. Food placed within the cavity and subjected to the microwave energy is thereby cooked. One problem, however, encountered in cooking food in a microwave oven is that the microwave energy is not dispersed uniformly within the heating cavity. The standing microwave pattern creates cold spots which cause the food to heat unevenly.
The industry, in response to the problem, have taken two main approaches toward a solution. The first is to improve the microwave energy source, through mode stirring or the like, so as to more evenly distribute energy within the oven cavity. Such attempts have to date not been entirely successful.
The second approach taken by the industry has been to develop rotatable turntables for use within the oven cavity. The turntable supports and moves food in a circular path to compensate for the effect of standing wave cold spots.
U.S. Pat. No. 4,504,715 teaches a turntable for use in microwave ovens comprising a turntable platform which is mounted to a stationary base. A motor, fixedly mounted on the center axis of the turntable, encased within a metallic pan drives a center shaft to thereby rotate the platform.
U.S. Pat. No. 4,330,696 discloses an alternatively configured turntable having a motor fixedly positionable adjacent to the turntable platform. The motor rotatably drives against an outwardly accessible gear ring which circumferentiates the turntable platform.
While the above available turntables function well and have been favorably received in the market, certain deficiencies prevent them from representing a complete solution to the industry's needs. First, the available turntables are relatively complex, making them difficult to assemble and expensive to manufacture. Further, such existing turntables are relatively large and can be difficult to fit into smaller ovens. Situating the motor outside of the turntable circumference as taught by U.S. Pat. No. 4,330,696 makes the turntable less space efficient. Finally, existing turntables only serve to minimize the effect of cold spots in the microwave oven cavity and do not address the cause of the problem.